Door Seals Leaking
 

I had a huge problem with my monte leaking, like a pond size amount of water, which I mostly fixed thankfully, by using a silicone sealant on the sunroof. (removed carpeting, no obvious signs of rust.) But the door seals still leak. On the drivers side door in the top corner, the seal on the door is torn for about five inches. But odly enough, the water still getting in, seems to be coming from the passenger side, which isnt cracked or torn, just old. How do I replace the old seals on the door and the frame?